Anatomical considerations in the repair of macrostomia.

Macrostomia is a deformity that occurs alone or in combination with other anomalies as a result of a failure of merging of the maxillary and mandibular processes of the first branchial arch. In an attempt to restore normal anatomy, a repair has been designed that includes provision of a lighter shade, rounded, nonrugated vermilion surface for the new oral commissure. The muscular ring is also reconstructed, and a Z-plasty is incorporated into the skin closure. In the patient described, an interesting band of fibrotic tissue was identified in the cleft, connecting the upper and lower orbicularis muscle bundles. Histologically, this tissue resembled scarred muscle fibers. A five-year follow-up is provided.